In the processing of sheets, such as business forms (which can be single paper thickness or multiple ply), there are many circumstances in which it is desirable to create a vertical stack of the forms, or other sheets, between processing steps. Some facilities wish to provide stacks of a wide variety of different types of sheets, which can be very difficult to accomplish utilizing conventional equipment. For example, some facilities wish to be able to sort or group, and stack, booklets, mailers, pressure seal forms and a wide variety of other types of business forms which ultimately are either shrink wrapped, banded together, stapled, bound, or the like. These different types of business forms have a wide variety of different widths and lengths, however, and also the optimum size of a stack varies greatly from one type of business form to another. Therefore, any equipment that is to accommodate this need must be readily adjustable and in a number of different manners. Also, it is important when forming stacks to make sure that the edges of the forms or other sheets are almost perfectly aligned with each other in order to facilitate further processing or handling.
According to the present invention, a relatively-simple and straight-forward variable cut sheet stacker is provided which is able to handle a wide variety of different sizes of business forms or other sheets, in a simple and effective manner, and may be easily adjusted to properly handle all sizes and types of common forms. The stacker according to the invention is also readily utilized with a wide variety of scanners or other equipment to effect separation between forms or other sheets for grouping and stacking, and is readily utilizable with conventional aligning mechanisms. A stacker according to the invention is also versatile, allowing center, right, or left alignment possibilities.
According to one aspect of the present invention a variable cut sheet stacker is provided comprising the following components: First and second side members which extend substantially vertically and are spaced from each other substantially horizontally. An inlet end support at an inlet for the stacker. An outlet end guide disposed opposite the inlet support horizontally spaced therefrom at an outlet for the stacker. A top conveyor for conveying cut sheets past the inlet support toward the outlet end guide, in a first direction. A bottom support vertically spaced from the top conveyor for supporting cut sheets. The inlet end support and outlet end guide, top conveyor, side members, and bottom support defining an open interior volume having substantially a rectangular prism configuration. Means for adjusting the relative positions of the side members with respect to each other. Means for adjusting the horizontal spacing of the inlet end support and the outlet end guide in the first direction. And, means for adjusting the vertical spacing of the top conveyor and bottom support.
The top conveyor typically comprises a frame that is pivotable about a horizontal axis substantially perpendicular to the first direction (preferably, at the outlet end of the stacker) to move between a conveyance position and an adjustment-facilitating position. The outlet end guide is preferably mounted on the top conveyor for pivotable movement therewith. The inlet end support preferably is fixed and includes an upper ramp which cooperates with the conveyor. The means for adjusting the horizontal spacing of the inlet end support and the outlet end guide may comprise any conventional device that allows linear adjustment of one guide component with respect to another. This may include pneumatic cylinders, cam operators, rotating screws with traveling nuts, or the like. In the preferred, simple structure according to the invention, the adjustment means comprises means for mounting the outlet end guide to the conveyor so that the outlet end guide is movable with respect to the inlet end support to adjust the position therebetween, such as a pair of guide rods mounted to the conveyor supporting frame. The guide rods are elongated in the first direction, and the outlet end guide comprises a vertical plate having openings for receiving the rods. Conventional bushings are provided in the opening so that when the vertical plate is moved to a position desired along the guide rods, it will stay in that position until moved again. If desired or necessary, detents or latching mechanisms may be provided for holding it in place.
The top conveyor typically includes first and second rollers rotatably mounted to the frame and extending substantially perpendicular to the first direction. At least one of the rollers--preferably the roller adjacent the outlet, where the pivoting action of the conveyor can take place--is driven by a conventional drive structure such as an electric motor connected to a shaft. A plurality of conveyor tapes or belts extend between the rollers, preferably having a substantially circular cross section, and being of elastic material. The inlet end support may comprise a guide cooperating with a plurality of conveyor tapes for positively guiding the tapes when moving in the first direction.
An eject means is preferably also associated and adjustable with the side members for, upon activation, moving sheets stacked in the interior volume out of the outlet end. The eject means may comprise conventional linear pushing elements, such as driven by pneumatic cylinders, rotatable screws with traveling nuts, or the like; however, preferably the eject means may comprise a pair of substantially-vertical paddles, either one or two mounted with each side member for movement with respect to each of the side members in the first direction. The paddles are mounted on a conveyance element, such as a tape or chain, the paddles extending outwardly from a conveyor belt. If two paddles are provided for each side member, then each paddle of a pair is spaced from the other about 180.degree. along the path of movement. The paddles may be moved in the first direction by any conventional drive mechanism, such as a conventional electric motor driving a shaft, and another drive shaft geared to the driven shaft to rotate the tape or chain to which the paddles are connected, a conventional clutch, etc. The paddle moving means typically also includes means for automatically stopping movement, for example after engaging an end-of-cycle tab and switch, the switch disengaging a clutch, or drive train, while the motor continuously runs, and the tab positively stopping movement of the paddle.
The inlet end support preferably comprises a central support substantially evenly spaced between the side members. The means for adjusting the positions of the side members with respect to each other move the side members uniformly toward and away from the central support. These adjusting means can be any suitable conventional structure and may be geared, ganged, or otherwise connected together for uniform movement. In the preferred embodiment, the means for adjusting the positions in the side members comprises a screw threaded shaft extending between the side members substantially perpendicular to the first direction, and a traveling nut portion of each of the side members for engaging the screw threaded shaft and linearly moving toward and away from the central support in response to rotation of the screw threaded shaft. The screw threaded shaft is rotated by a conventional hand crank, or by an electric motor.
The means for adjusting the vertical spacing of the top conveyor and bottom support also may comprise any suitable conventional structure. For example, a number of different support trays may be provided that can be inserted into the interior volume and have various heights and interior length and width dimensions, and may be fastened in place by magnets, pins and/or the like. Alternatively, the vertical spacing can be provided by mounting the bottom support on one or more pneumatic cylinders that are moved up and down depending upon the height of the interior volume desired. By utilizing pneumatic cylinders, or like linear actuators, for moving the bottom support up and down, it is not necessary to adjust the position of an outfeed conveyor, but rather the bottom support may be moved to vertical alignment with an outfeed conveyor and then the paddles are actuated to eject the forms from the interior volume onto the outfeed conveyor.
Preferably, the means for adjusting the relative positions of the side members with respect to each other, the means for adjusting the horizontal spacing of the inlet end support and the outlet end guide in the first direction, and the means for adjusting the vertical spacing of the top conveyor and bottom support, collectively provide for adjustment of the internal volume from between approximately 3.5 inches by 3.5 inches by 1 sheet thick in height, and approximately 12 inches by 12 inches by 3 inches (height).
The stacker according to the invention also is preferably associated with, and in combination with, a conventional sheet aligner (such as shown in U.S. Pat. No. 5,267,731, the disclosure of which is incorporated by reference herein) for aligning the edges of sheets just prior to engagement with the top conveyor. Just before the edge aligner may also be provided an infeed conveyor which accommodates bar code scanning or other types of scanning, or a fixed counter, which allows proper grouping of the stack. That is, the number of forms or other sheets that are desired to be placed into a stack may be counted at the infeed conveyor, or the last form in a stack having a bar code or other sense mark thereon scanned, which then--after a short time delay--signals the equipment feeding the stacker infeed conveyor to stop feeding forms (or temporarily arrests an infeed conveyor), moves the bottom support into proper position for ejecting the forms from the interior volume, actuates the paddles to eject the forms, and then moves the bottom support to its initial position. Means are provided (such as guide rods) for mounting the stacker for horizontal adjustment with respect to the aligner in a direction substantially transverse to the first direction to allow left edge, right edge, or center alignment.
According to another aspect of the present invention, a variable sheet stacker is provided comprising the following components: First and second side members which extend substantially vertically and are spaced from each other substantially horizontally. An inlet end support at an inlet for the stacker. An outlet end guide disposed opposite the inlet support horizontally spaced therefrom at an outlet for the stacker. A top conveyor for conveying cut sheets past the inlet support toward the outlet end guide, in a first direction. A bottom support vertically spaced from the top conveyor for supporting cut sheets. The inlet end support and outlet end guide, top conveyor, side members, and bottom support defining an open interior volume having substantially a rectangular prism configuration. And, wherein the top conveyor comprises a frame that is pivotal about a horizontal axis substantially perpendicular to the first direction and adjacent the outlet to move between a conveyance position and an inoperative position. The details of all of the components may be as set forth above.
According to yet another aspect of the present invention, a variable cut sheet stacker is provided comprising the following components: First and second side members which extend substantially vertically and are spaced from each other substantially horizontally. An inlet end support at an inlet for the stacker. An outlet end guide disposed opposite the inlet support horizontally spaced therefrom at an outlet for the stacker. A top conveyor for conveying cut sheets past the inlet support toward the outlet end guide, in a first direction. A bottom support vertically spaced from the top conveyor for supporting cut sheets. The inlet end support and outlet end guide, top conveyor, side members, and bottom support defining an open interior volume having substantially a rectangular prism configuration. And, eject means associated with the side members for, upon activation, moving sheets stacked in the interior volume out the outlet end. The details of all of the components may be as described above.
It is the primary object of the present invention to provide a simple, effective, yet readily-adjustable cut sheet stacker for use with a wide variety of sheets, particularly business forms. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.